Board Thread:General Discussion/@comment-30714188-20161225010131/@comment-27248965-20161228133051

If your Lucario has a nature that boosts Physical Attack, I'd agree with what Jinx said. In addition to the moves above, you can also have Swords Dance to boost its Phy. Atk faster. Bone Rush is a nice coverage move if you don't have TM Earthquake.

If your Lucario has higher Special Attack, I'd go for 252 Sp. Atk and 252 Speed. In this case, Aura Sphere is a must, while Flash Cannon is also necessary once the TM for it comes out. Nasty Plot is learnt by Riolu at Lv.47, if you cannot prevent Riolu from evolving for that long, Calm Mind is a nice alternative.